Peter Fredrik Holst (23 December 1861 – 5 January 1935) was a Norwegian physician, a professor of internal medicine and specialist in bacteriology and cardiology.

[2] Holst graduated as physician in 1888, and was assigned at Lungegaardshospitalet in Bergen, where he worked with Daniel Cornelius Danielssen and Gerhard Armauer Hansen.

He was appointed professor of internal medicine at the Oslo University Hospital, Rikshospitalet from 1902 to 1932.

He edited a widely used textbook in internal medicine, where he wrote the part on cardiology, and this work is regarded his most significant scientific contribution.

[1][3] Holt was awarded honorary doctoral degrees at universities in Stockholm, Copenhagen and St Andrews.